Rock drill



Nov. 13, 1928.

C. F. OSGOOD Rocx DRILL Filed June 2, 1927 Any.

Patented Nov. 13, 1928.

UNITED l STATES 1,691,405 PATENT OFFICE..

CHARLES F. OSGOOD, OF CLAREIVIONZT, NEW HAMPSHIRE, ASSIGNOR TO SULLIVANMACHINERY COMPANY, CORPORATION F MASSACHUSETTS.

`ROCK DRILL.

Application filed .Tune 2,

This invention relates to rock drills andv more particularly to a holeblowing device for fluid actuated rock drills of the hammer type.

'An object of this invention is to provide anV improved hole blowingdevice for rock drills. Another object is to provide an improved holeblowing device for fluid actuated rock drills of the hammer type wherebythe fluid distribution valve is held immovable to effect a. holeblowingoperation. Still another object of this invention is to admit anuninterrupted supply of pressure fluid to the drill steel for cleansingthe drill hole and to hold the distribution valve and hammer pistonimmovable while said pressure fluid is flowing through the drill steel.A further object is to provide an improved hole blowing device for afluid actuated rock drill wherein the automatic fluid distribution valveis pneumatically held in position to effect a hole blowing operation.These and other objects and advantages of this invention will, however,subsequently more fully appear.

In the accompanying drawing there is shown for purposes of illustrationtwo forms which the invention may assume in practice.

In this drawing,- Fig. 1 is a central, longitudinally extending-verticalsectionalY viewv through a rock ldrill embodying the improved holeblowing device, the parts being shown in position to effect aholeblowing operation. p

Fig. 2 is a detail sectional view similar to that shown in Fig. 1,showing the parts in a different position. I Y

Fig. 3 is a detail sectional view illustrating a slightly modified formofconstruction.

1u this illustrative construction there is shown a rock drill of thepressure fluid actuated impact type comprising a ,cylinder 1 having abore 2 in which a hammer piston 3 is reciprocably mounted. The hammerpiston 3 is provic ed with avforwardly projectingl striking bar 4Cmovably mounted withinv'a bore 5 formed wit-hin the usual kfrontcylinder head 6 and this striking bar is adapted to impart a series ofblows onthe shank of a hollow drill steel 7. The drill steel T isloosely mounted in a .usual manner within a chuck bushing 8 secured to achuck sleeve 9 rotatably mounted within a usual chuck housing` 10. Asillustrated, the rear end of the cylinder bore is closed bya washer 11while interposed betweenthis washer and 1927. Serial No 196,108.

a rear head member 12 is a usual ratchet ring 13. The chuck housing andfront cylinder head 6, cylinder 1, rear washer 11, the rear head 12andthe ratchet ring 13 are held to gether in a suitable and convenientmanner. for instance by usual side bolts or rods (not shown).

In order to impart a rotary movement to the hammer piston 3 during oneof its strokes, preferably during the rearward stroke, for rotating thedrill steel 7, a spirally grooved rifle bar 14 extends throughthe washer11 to engage the hammer piston 3 in the usual manner. The means forholding the rifle bar 14 immovable during one stroke of the piston andfor permitting rotation of the rifle bar during the opposite strokeofthe piston consists of a usual ratchet and pawl device generalydesignated 15. Rotary movement of the piston is transmitted to the drillsteel 7 by means of straight flutes 16 formed on the periphery yof thestriking bar 4. The flutes 16 engage straight lugs 17 formed on a chucknut 18 secured to the rotatable chuck sleeve 9.

Herein preferably formed integral with the cylinder 1,' is a valve chest19 in which a valve chamber 20 is formedto receive an automatic fluiddistributingI valve 21. The fluid distributing valve 21 may be of anysuitable type as the invention is not depend ent upon the particularvalve illustrated or its successful functioning and the invention may beused in connection with any type of valve which `controls 'both theadmission of pressure fluid to the cylinder and the eX- haust ofpressure fluid therefrom. The valve 21 in this instance is of the wellknown three-spool differential type having an enlarged central spool 22and reduced end spools 23. The central spool v22 controls the admissionof pressure fluid through an inlet 24; into the valve chamber 20 and theend spools 23 have opposed actuating faces 25 and 25a respectivelyagainst which pressure fluid .chamber 20 to atmosphere. Pressure fluidVmay* act for moving the distribution valve admitted into the chamber 20may pass to the 'y exhausting the pressure fluid fromthe cylinder.Suitable butler plugs 30 and 31 are provided for limiting movement ofthe valve in opposite directions.`

Usually in rock drills employing the type of valve herein described,throwing passages are employed for admitting pressure fluid from thecylinder to act against the actuating faces of the valve. Such throwingpassages may be crossed as in the present instance in which a throwingpassage 32 leads from the front end` of the cylinder bore 2 to therearward end of the valve chamber 2O and is controlled by the hammerpiston 3. A second piston controlled throwing passage 33 leads from therear end of the cylinder bore 2v tothe front end of the valve chamber2U.

The improved hole blowing device com prises a reciprocabie plunger valve34 extending through a central bore 35 inthe distribution valve 21 andslidably mounted in bores 36 and 37 formed in the butler plugs 30 andv31 respectively. r1`he plunger valve 34 externally grooved at 38 and 39'at points spaced longitudinally thereof and is provided at its forwardend with a conveniently located push button 40. As shown. the bufferplug 30 has formed therein radial ports 41 connecting the bore 36 withthe valve chamber at the rear 'end of the valve 21. Also formed in thebuffer plug'` 30 and adjacent portions of the valve chest are radialports 42 which connect the bore 3G with the atmosphere. The buffer plug31 is provided `*with radial ports 43.which connect the bore 37 With thevalve chamber at the forward end of the valve 21 and is also providedwith radial ports 44 which connect the bore 37 with an annular groove45. The groove 45 is connected througha passage 46 with the pressurefluid inlet 24. In this instance, vthe plunger valve v34 is held in itsreleased or inoperative positiony as shown in Fig. 2 by means of acoiled spring 47 seated within a bore 48 formed in the buffer plug` 31and engaging a transverse pin 49 carried by the valve 34. Asillustrated, the'valve 34 hasforined centrally therein restricted ventpassages 50 and 51 which connect the valve chamber at the opposite endsof the valve 21 to atmosphere when the plunger valve 34 is in itsreleased position as shown. in Fig. 2.

In the modiiication shown in Fig. 3, the structure is generally the sameas that described above in Figs.l 1 and 2 with the except-i on that thepush button 40 and the spring 47 for holding the valve in its releasedposition are located at the rear end of the `valve This arrangementpermits Vthe plunger valve 34 to be operated from the rear end of thedrill by simply sliding the valve forwardly to effect a hole blowingoperation. In view of the factthat the valve is te be operatedin thereverse direction from that shown in Figs. 1 and 2, the location ofannular grooves 38 and 39 relative to passages in the butler plugs ischanged correspondinglyI so as to establish communication between ports41 and 42 and betweenl ports 43 and 44 upon. a forward movement of thevalve, and to cut off such communication in the normal rearward positionof the valve.

In the normal operation of the rock drill, pressure fluid flows throughinlet passage 24 and when the distribution valve 21 is in the 29 pastthe rear surface of the front end A spool of the distribution valve 21and through the exhaust passage 27 to atmosphere. The distribution valve21 is held in'its forward position by reason of the larger effectivearea of the central spool. When the hammer piston uncovers the throwingpassage 33, pressure iriuid is admitted from the rear end of thecylinder bore to the forward end of' the valve 21 and consequently thelatter is thrown rearwardly to the position shown in Fig. 1. Pressurefluid nowenters the forward end of the cylinder bore through inletpassage 24, past the forward surface of the central spool22 on the valveand through the passage 29 and consequently the hammer pisten is movedrearwardly.y The exhaust now takes place through passage 28 past theforward surface of the rear spool 23 of the distribution valve andthrough the exhaust passageV 26 to atmosphere. The restricted ventpassages 50 and 51 inthe plunger valve 84 prevent any back pressure frombuilding up in the valvechamber at the opposite ends of the distributionvalve and as a result, the valve action is materially quickened. As soonas the piston 3 has uncovered the throwing passage 32, the distributionvalve 21 is again shifted to its forward position andthis cyclecontinues during the normal operation of the drill. V

When it is desired to eifect a hole blowing operation, the operatorpresses against the push button 40 and moves the plunger valve V 34rearwardly from the position shown in Fig. 2 to the position shown'inFig. 1. When .theplunger valve 34 is in the position shown in Fig. 1,the groove 38 connects the radialV ports 41 and 42 and consequently thevalve chamber at the rear end of the'valveV 21 is vented to atmosphere.Simultaneously the groove 39 connects the radial ports 43 and'44 andconsequently live pressure Huid is adnmitted from the inlet 24 throughpassage 46 and groove 45 to the valve chamber at the vforward end of thevalve. VResultantly,the

throwing pressure acting on the actuating face 25 of the valve isrelieved and at the same time a pressure is built up against theactuating face 25a on the valve 21, shifting the valve 21 to its eXtremerearward position and pneumatieally holding'the sameimmovable. vWhen thevalve 21 is held in its retracted position as shown in Fig. 1, pressurefluid flows from the inlet 24 past the f orward surface of the centralspool 22 of the distribution valve and through the passage 29 to theforward end of the cylinder bore. The continuous pressure flowing tothis end of the cylinder vbore forces the piston 3 rearwardly againstthe rear cylinder washer 11 and consequently pressure fluid flows fromthe cylinder bore through the flutes 16 on the striking bar e, throughthe chuck nut 18, and thence through the bore in the drill steel to thebottom of the drill hole. As soon as the manual pressure on the pushbutton 10 is released, the plunger valve 34 is automatically returned toits inoperative position and the distribution valve 21 will then resumeits normal operation and the drill will again function in a normaln'ianner. The operation of the modification shown in Fig. 3 issubstantially the same as that described above with the exception thatthe plunger valve is moved forwardly to vent the rear end of the valvechamber 20 to atmosphere and'to supply live fluid to the front end ofthe valve chamber. These and other uses and advantages of this inventionwill be clearly apparent to those skilled in this art.

lVhile I have. in this application 'specifically described two formswhich my invention may assume in practice, it will be understood thatthese forms of the same are shown for purposes of illustration and thatthe invention may be modified and embodied in various other formswithout departing from its spirit or the scope of the appended claims.

lhat l claim as new and desireto secure by Letters Patent is:

1. In a fluid actuated rock drill ofthe hammer type, the combination ofa cylinder yand a piston reciprocable therein, Va valve chest and afluid distributing valve therein controlling both the supply and exhaustof pressure fluid for said cylinder, valve throwing v passages betweenopposed spaces in the valve chest and the cylinder bore for supplyingpressure fluid for actuating said valve, and a hele blowing' devicecomprising a member arranged coaxially with saidfluid distributingvalve, valve means controlled by movement thereof for admitting pressureYfluid to one valve chest space and valve means also controlled bymovement'of' said member for venting the opposed space to atmospherewhereby said distributingvalve is pneuinfatically held immovable toeffect a hole blowing operation.

2. n a fluid actuated roel; drill ofthe hammer type, theV combination ofa cylinder and a piston reciprocable therein, a valve chest and a fluiddistributing valve therein controlling both the. supply and exhaust ofpressure fluid for said cylinder, valve throwing passages betweenopposed spaces in the valve chest and the cylinder bore for supplyingpressure fluid for actuating said valve, and a hole blowing devicecomprising a member arranged coaxially with said fluid distributingvalve and extending therethrough, means carried by said member foradmitting pressure fluid to one valve chest space and means controlledby movement of said member for venting the opposed space to atmospherewhereby said distributing valve is pneumatically held immovable toeffect a hole'blowing operation. l

3. In a fluid actuated reel( drill of the hammer type, the combinationof a cylinder and l a piston reciprocable therein, a valve chest and afluid distributing valve therein controlling both the supply and exhaustof pressure fluid for said cylinder, valve throwing passages betweenopposed spaces in the valve chest and the cylinder bore for supplyingpressure fluid for actuating said valve, and a hole blowing devicecomprising an auxiliary valve arranged coaxially with said fluiddistributing valve having fluid conducting means for admittingl pressurefluid toY one valve chest space and also having fluid conducting meansfor venting the opposed space te atmosphere whereby said distributingvalve is pneumatically` held immovable to effeet a hole blowingoperation. f

el. In a fluid actuated rock drill of the hammer type, the combinationofI a cylinder and a piston reciprocable therein, a valve chest and afluid distributing valve therein controlling both the supply and exhaustof pressure fluid for said cylinder, valve throwing passages betweenoppcsed spaces yin the valve chest and the cylinder bore for supplyingpressure fluid for actuating said valve, and a hole blowing devicecomprising an auxiliary valve arranged coaXially with said fluiddistributing valve and extending therethrough and having fluidconducting means adjacent one end for admitting pressure fluid to onevalve chest space and fluid conducting means for venting the opposedspace to atmosphere whereby said distributingvalve is pneumatically heldimmovable to effect a hole blowing operation.

5. In a fluid actuated rock drill of the hainmer type, the combinationof a cylinder and a piston reciprocable therein, a valve chest and afluid distributing valve therein controllingy both'th'e supply andexhaust pressure fl fory said cylinder, valve throaving passages betweenoppesed spaces in the valve chestand jthe cylinder-bore for supplyingpressure fluid for actuating said valve, aud a hele blowing devicecomprising a manually operable reciprocable plunger valve arrangedcoaxially with said distributing' valve having vfluid conducting meansfor admitting pressure fluid to an area of said Valve tending to opposesaid shifting thereof.

l2. ln a Huid actuated rock drill of the hammer typev` Jthe combinationof a cylinder and a piston reciprocable therein', a Valve chest andfluid distributing valve therein controlling both the supply and exhaustof pressure Huid for said cylinder, Valve throwpassages between opposedspaces in the Valve chest and the cylinder bore for supplying pressurefluid for actuating said Valve, and a holeblowing device including meansfor Venting the space at one end of the Valve to atmosphere, said meansincluding an element extending through said Valve and manually operablefrom the opposite end of the valve.

13. In a liuid actuated rock drill of the hammer type, the combinationof a cylinder and a piston reciprocable therein, a valve chest and afluid distributing Valve therein controlling both the supply andyexhaust of pressure fluid for said cylinder, Valve throwing passagesbetween opposed spaces in the valve chest and the cylinder bore forsupplying pressure fluid for actuating said Valve, means including anauxiliary Valve l'or Venting the valve chest space at one end of saidvalve to atmosphere during a hole blowing operation, and means forventing said valve chest spaces to atmosphere during normal operation ofsaid fluid distribution valve including vent means formed in saidauxiliary Valve.

14. In a fluid actuated rock drill of the hammer type, the combinationof a cylinder and a piston reciprocable therein, a yValve chest and afluid distributing valve therein controlling both the supply and exhaustof pressure fluid for said cylinder, valve throwing passages betweenopposed-v spaces in said valve chest and the cylinder bore for supplyingpressure fluid for actuating said valve, and a hole blowing deviceincluding an auxiliary valve arranged coaxiallyk with and eX- tendingthrough said distributing valve Inanually operable. from the forward endof said distributing Valvey for venting the Valve chest space at therear end of' said distributing Valve to atmosphere during a hole blowingoperation.

Intestimony whereof I aliix my signature.

CHARLES F. OSGOOD.

